| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47594: mptcp: never allow the PM to close a listener subflow |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mptcp: never allow the PM to close a listener subflow |
| |
| Currently, when deleting an endpoint the netlink PM treverses |
| all the local MPTCP sockets, regardless of their status. |
| |
| If an MPTCP listener socket is bound to the IP matching the |
| delete endpoint, the listener TCP socket will be closed. |
| That is unexpected, the PM should only affect data subflows. |
| |
| Additionally, syzbot was able to trigger a NULL ptr dereference |
| due to the above: |
| |
| general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN |
| KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] |
| CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0 |
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 |
| RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897 |
| Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff |
| RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016 |
| RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000 |
| RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001 |
| RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 |
| R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000 |
| R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001 |
| FS: 00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0 |
| Call Trace: |
| <TASK> |
| lock_acquire kernel/locking/lockdep.c:5637 [inline] |
| lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 |
| __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] |
| _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 |
| finish_wait+0xc0/0x270 kernel/sched/wait.c:400 |
| inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline] |
| inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497 |
| mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865 |
| inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739 |
| mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345 |
| do_accept+0x382/0x510 net/socket.c:1773 |
| __sys_accept4_file+0x7e/0xe0 net/socket.c:1816 |
| __sys_accept4+0xb0/0x100 net/socket.c:1846 |
| __do_sys_accept net/socket.c:1864 [inline] |
| __se_sys_accept net/socket.c:1861 [inline] |
| __x64_sys_accept+0x71/0xb0 net/socket.c:1861 |
| do_syscall_x64 arch/x86/entry/common.c:50 [inline] |
| do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 |
| entry_SYSCALL_64_after_hwframe+0x44/0xae |
| RIP: 0033:0x7f177cd8b8e9 |
| Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 |
| RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b |
| RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 |
| RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000 |
| R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c |
| R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000 |
| </TASK> |
| |
| Fix the issue explicitly skipping MPTCP socket in TCP_LISTEN |
| status. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47594 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13 with commit 740d798e8767d8a449902b1a1bbc70facfce19b5 and fixed in 5.15.11 with commit 1456a0004cc54c58adb2501cb0c95dc8b3c83e9e |
| Issue introduced in 5.13 with commit 740d798e8767d8a449902b1a1bbc70facfce19b5 and fixed in 5.16 with commit b0cdc5dbcf2ba0d99785da5aabf1b17943805b8a |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47594 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/mptcp/pm_netlink.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/1456a0004cc54c58adb2501cb0c95dc8b3c83e9e |
| https://git.kernel.org/stable/c/b0cdc5dbcf2ba0d99785da5aabf1b17943805b8a |
